What is the newest installment of 'Random Thoughts' on Physics Forums?

[berkeman]

Too much generation, nowhere to send the surplus.
https://www.msn.com/en-us/money/mar...ff-from-national-electricity-grid/ar-AA146XXm

Wow, talk about weird modern problems...

 

[Astronuc]

AP News reports Russian missiles crossed into Poland killing two people!
https://apnews.com/article/russia-ukraine-war-zelenskyy-kherson-9202c032cf3a5c22761ee71b52ff9d52

A large number of missiles strike civilian infrastructure in Ukraine.

 

[Orodruin]

AP News reports Russian missiles crossed into Poland killing two people!
https://apnews.com/article/russia-ukraine-war-zelenskyy-kherson-9202c032cf3a5c22761ee71b52ff9d52

A large number of missiles strike civilian infrastructure in Ukraine.

This was more or less bound to happen at some point. The big question is what will happen next. Poland is a member of NATO and will not be happy to have their own citizens killed in their own territory by Russian missiles.

 

[WWGD]

How do you explain to a high-school kid the meaning of " $x^2+1$ has no Real solution, but$z^2+1$has a Complex solution", without using heavy machinery like Field extensions?

 

[Astronuc]

How do you explain to a high-school kid the meaning of " $x^2+1$ has no Real solution, but$z^2+1$has a Complex solution", without using heavy machinery like Field extensions?

Does one mean $x^2+1 = 0$? I thought that was when $x = i$, which was explained when I first learned about complex number, probably in high school.

And then more generally, $z = x + iy$

 

[fresh_42]

How do you explain to a high-school kid the meaning of " $x^2+1$ has no Real solution, but$z^2+1$has a Complex solution", without using heavy machinery like Field extensions?

Riemann sphere?

 

[WWGD]

Does one mean $x^2+1 = 0$? I thought that was when $x = i$, which was explained when I first learned about complex number, probably in high school.

Yes, I meant $x^2+1=0$. But appealing to Complex numbers alone seems not tobe satisfying. Not sure what would be " Natural "to them.

 

[Astronuc]

Yes, I meant $x^2+1=0$. But appealing to Complex numbers alone seems not tobe satisfying. Not sure what would be " Natural "to them.

Not too many kids are ready for fields and n-dimensions in high school, and many don't get it even at university. I've met very few who could understand abstract algebra (incl. groups, rings, and fields) or complex analysis.

 

[Haborix]

I don't see what more you can do than have them convince themselves that if there were a solution, its square would have to equal $-1$. Then have them convince themselves there is no such real number. It isn't going to cook up all the beautiful structure of complex analysis but it will get the idea of something more than the reals in their heads.

 

[fresh_42]

I don't see what more you can do than have them convince themselves that if there were a solution, its square would have to equal $-1$. Then have them convince themselves there is no such real number. It isn't going to cook up all the beautiful structure of complex analysis but it will get the idea of something more than the reals in their heads.

Again, the Riemann sphere provides an alternative. Draw the parabola on a sheet of paper

and clue all four corners such that we get a sphere. Extending the parabola on the sphere result in two intersections of the $x$-axis that weren't there before.

At least, I think this would work.

 

[Astronuc]

Why Train Tickets Are so Expensive in the U.S.
https://news.yahoo.com/why-train-tickets-expensive-u-220000637.html

It's the market and the particular business. How to make it better. Transportation systems are capital intensive and require substantial maintenance.

 

[WWGD]

Why Train Tickets Are so Expensive in the U.S.
https://news.yahoo.com/why-train-tickets-expensive-u-220000637.html

It's the market and the particular business. How to make it better. Transportation systems are capital intensive and require substantial maintenance.

As I understand, population density in most of the US makes it hard to break into the black. That's outside of a few regions like the NE corridor.

 

[Astronuc]

As I understand, population density in most of the US makes it hard to break into the black. That's outside of a few regions like the NE corridor.

Population density and utilization are important factors. In the case of the Northeast Corridor, Amtrak, more or less owns, or at least controls the track. Outside of the NEC, particularly for inter-city trains, Amtrak leases access to the rails. Amtrak, of course, took over the rail passenger service from the railroads that traditionally provided the service, as it became unprofitable. City and regional organizations took over much of the commuter rail service, and for some regions, states and local governments subsidize Amtrak.

Part of the revenue from passenger service came from shipping mail, which subsequently went to trucks and airlines, and the loss of mail revenue made most passenger trains unprofitable.

The challenge is how to make Amtrak profitable, and that is quite a challenge.

I have used Amtrak to travel to Washington DC, then use the DC Metro to get around. I found it more or less affordable, since I don't need to drive or fly, and even flying requires driving to the airport, waiting, then flying. From Washington DC airports, Washington National (Reagan) or Dulles, one can ride a DC Metro train. For me by myself, it is practical to take the train (Amtrak), but with multiple people, it's perhaps more practical to drive, depending on where in DC, and now long, and how many others.

 

[fresh_42]

Spoiler: I miss the English queen

Boudica.

 

[BillTre]

Universal problem for coaches:

 

[BillTre]

Ever wonder how non-moving plants get spread around so much?

 

[berkeman]

Really nice short video that came into my Facebook feed today:

 

[Astronuc]

Chichester: Care home resident, 84, returns to school for physics GCSE
https://www.bbc.com/news/uk-england-sussex-63735319

An 84-year-old care home resident who failed his physics exam five times has returned to school after 66 years to fulfil a dream to complete his secondary education.

Ernie Puffett has returned to class to take weekly physics lessons at Chichester College in West Sussex.

He said he would be "elated" if he passed GCSE physics next summer.

College principal Helen Loftus said there were "so many benefits" to having students of all ages in the classroom.

 

[WWGD]

Chichester: Care home resident, 84, returns to school for physics GCSE
https://www.bbc.com/news/uk-england-sussex-63735319

I know of someone in their 70s who's considering doing that.

 

[Mayhem]

My workflow for writing reports/articles in anything other than LaTeX is absolute trash.

 

[Astronuc]

Don't fool with Nature - but of course we do.

https://www.nationalgeographic.com/...ince-the-mayor-and-the-us-fish-that-ate-japan

The prince, the mayor, and the U.S. fish that ate Japan​

An innocent gift from Chicago to Prince Akihito in 1960 caused a decades-long ecological crisis that Japanese scientists are now close to solving.

Will CRISPR work?

 

[WWGD]

New claim, at least to me, that ( drinking) water is beneficial because it flushes the kidneys, but that is far from being the best at hydrating, in that a smaller portion of it is retained over time by the body than the portion of other liquids that is retained.

 

[fresh_42]

Fastest US car on Famost German Race Track (Nürburgring Nordschleife, 20.832 km = 12.944,4 mi)

Spoiler: Corvette

Sorry, you lost.

Spoiler: Viper

Congratulations! Dodge Viper ACR (2017, manual) in 7:01.3

 

[WWGD]

I should have specified I was talking about Bayes when I said I liked her posterior.

 

[DrGreg]

Today I heard the phrase "pile-on" being used in a TV discussion about abuse on social media. I wasn't giving the TV my full attention (multi-tasking) and hadn't heard this phrase used in this context before, so I thought they said "pylon", and was confused why electricity transmission towers were relevant to the topic under discussion.

 

[Astronuc]

SF Chronicle has compiled some obituaries of those who died from/with Covid-19. One page belongs to those just from Connecticut. I haven't looked further since there are over 1 million deaths in the US.

Arnold J. Cantor, a distinguished scholar, earned a PhD in Physics from Harvard where he occasionally corresponded with Albert Einstein, his obituary said. He applied his knowledge of lasers and aeronautics through his work at Sylvania, Mitre and United Technologies. He was not only a gifted and brilliant theoretical physicist, but also warm, loving, kind, funny and generous. He leaves a body of poetry spanning sixty years which he shared on his website and at the Bloomfield Library poetry readings. Later in life, he engaged in a diversity of courses at the President's College at the University of Hartford as well as becoming an avid and skilled birder.

https://projects.sfchronicle.com/2020/connecticut-coronavirus-obituaries/
The long list seems to be only for March-July 31, 2020 during the initial wave of SARS-Cov-2

https://www.legacy.com/us/obituaries/hartfordcourant/name/arnold-cantor-obituary?id=2187846

Physicist, Artist, Poet, and Naturalist Arnold Jules Cantor (~87) of Bloomfield CT (formerly of West Hartford, CT and Lexington, MA) passed away at St. Francis Hospital in Hartford on July 6th, 2020 of Covid-19 after a long struggle with dementia. Arnold was a distinguished scholar graduating Magna Cum Laude in Physics from Brooklyn College where he was President of the Physics Society. He earned a PhD in Physics from Harvard where he was a recipient of a Corning Glass Works Foundation Fellowship and a member of Phi Beta Kappa and Pi Mu Epsilon honor societies. He applied his knowledge of lasers and aeronautics through his work at Sylvania, Mitre and United Technologies.

 

[Astronuc]

The Telegraph - Coal miner’s daughter and ex-White House aide new chancellor of Durham University
https://www.yahoo.com/news/coal-miner-daughter-ex-white-213947997.html

A coal miner’s daughter who became a White House foreign policy adviser has been appointed chancellor of Durham University.

Dr Fiona Hill, who has worked for US presidents George W Bush, Barack Obama and Donald Trump, was selected on Monday to become the ceremonial head of the university in the county where she grew up.

 

[pinball1970]

We have just started the match with the Welsh (world cup Association football)
Why did Wales have a different national anthem?

 

[WWGD]

We have just started the match with the Welsh (world cup Association football)
Why did Wales have a different national anthem?

Or a different team? Ive always been curious about the status of the member states of the UK. Are they formally countries?

 

[pinball1970]

Or a different team? Ive always been curious about the status of the member states of the UK. Are they formally countries?

It's UK national anthem. Different team and country but there is one national anthem